Method of treating hydrocarbon motor fuels



Patented May 5, 1936 UNITED STATES PATENT OFFICE METHOD OF TREATDIG HYDROCABBON MOTOR- FUELS Julius Hyman and George W. Ayers, In, Chicago,

Ill.,. assignors, by mesne line Antioxidant Company,

assignments, to Gaso- Wilmington. DeL,

a corporation of Delaware No Drawing.

Application January 18, 1930, Serial No. 421,866

3 Claims. (01. 44-9 into similar compounds having approximately the.

boiling range of gasoline. Many cracked gasolines upon being exposed for some time to air, form resinous materials which may be dissolved by the oil or may form insoluble deposits. These resinous compounds are formed particularly in large amounts in gasoline produced by vapor phase cracking, which gasolines contain a large percent of unsaturatedcompounds. 'When such gasolines are exposed, under ordinary conditions of commercial handling, to heat, light and air,

such unsaturated hydrocarbons react rapidly in producing the aforesaid gums or undesirable resinous products. If the latter are permitted to form and remain in the motor fuel they are apt to interfere with the proper flow of the fuel through the restricted passagesof internal combustion engines by producing deposits of such gums in said passages to an extent sufficient to clog or obstruct the passages against the free or proper flow of the fuel to the combustion cylinders.

It is, therefore, an outstanding object of the present invention to provide a cracked hydrocarbon motor fuel to which are added compounds, which for convenience in description may be termed negative catalysts or gum inhibitors", which will arrest for all practical purposes the formation of the objectionable resinous or gum compounds in the motor fuel product to the .end that the latter may be subjected to the conditions prevailing in the storage, transportation and handling of motor fuels without any appreciable development or formation of the objectionable gum substances in the fuel. 3

This application is a continuation in part of our earlier application Serial No. 309,685, filed October 1, 1928.

It has been discovered that certain substances when added to cracked petroleum gasolines retard the rate of formation of these resinous products. When p-aminophenol is added to a motor fuel 011 containing unsaturated compounds, gum formation in such oils will be prevented substantially entirely under ordinaryconditions of handling and storage for periods of several months.

The following table discloses results of gum free and gum-stable motor fuel from vapor phase tests on vapor phase gasoline towhich various anti-gum compounds have been added:

Begin 66days 96 days 230 days 400 days Blank 0010 0369 0609 0594 2521 p-Aminophenol. 0010 0012 0013 0010 0014.

From the foregoing it will be seen that by the addition of p-aminophenol to cracked motor fuels, 10 particularly fuels containing large percentages of unsaturated compounds, the fuels are stabilized for all practical purposes in so far as the formation of gum compounds is concerned. This discovery is of far reaching importance in the manufacture of synthetic or cracked gasolines. The tendency at the present time in the manu-' facture of motor fuels is to produce motor fuels having a high anti-knock value, and such fuels readily produce gums when exposed to light and 20 air under ordinary conditions of handling, even after careful purification treatment with fullers earth and similar polymerizing processes. The preferred method of treating such oils consists in passing the cracked oils obtained directly from 25 a cracking system while in a vaporous state into contact with a polymerizing catalyst such as fullers earth, which accelerates the formation of the polymers or gum compounds to permit of the removal of the'latter to a very large extent from 30 the oils at the time the latter are manufactured. Then to prevent further formation of gums in the purified or polymer-freed oils, the present invention employs as a gum inhibitor p-aminophenol, which may be added in relatively small 35 quantities, substantially ten pounds per thousand barrels of the cracked distillates to overcome further gum formation during ordinary handling, storage and transportation of the fuel. This insures delivery to the ultimate consumer of a gumfree motor fuel which will not produce resinous deposits in the small fuel passages of an internal combustion engine or associated parts, and especially permits of the use of a pure hydrocarbon motor fuel possessing high anti-knock value without the presence of objectionable and obnoxious gum deposits.

What is claimed is:

l. The method of preparing substantially gum- 50 cracked mineral oil which consists in contacting cracked oils boiling within the gasoline range with selective polymerizing catalyst under temperature and pressure conditions to maintain a substantial adding to the degummed oil a small quantity of gum inhibitor suflicient to inhibit fiu'ther tarmationoigum. Y

2. Methodin accordance with claim 1 in which the inhibitor is an amino-phenol capable of inhibiting gum formation in cracked gasoline.

3. The method of preparing substantially gumfree and gum-stable motor fuel from vapor phase 10 cracked mineral oil which consists in contacting ,cracked oils boiling within the gasoline range, at temperatures suiliciently high to maintain said oils in the vapor phase, with a selective polymerizing catalyst in order to remove gum and gumforming constituents, and then adding to the degummed oil a small quantity oi gum inhibitor sufiicient to inhibit further formation 01 gum. 

